Minimization of reactor noise through external control

An analytical approach based on the work of Wiener is taken to develop an expression for an optimum linear feedback control system that will minimize the random variations in the flux of a nuclear power reactor. The optimization criterion is the minimization of the mean-square value of these random variations. In determining the optimum control system transfer function, an acceleration constraint is placed on the control-rod drive mechanism. To demonstrate the technique presented, an optimum control system transfer function is derived for the experimental boiling water reactor (EBWR) under specified operating conditions. The changes in the mean-square value of reactor flux caused by varying acceleration constraint level is discussed. Results show that a considerable reduction in the mean-square value of the random flux variations can be obtained through external control.